Back when we pulled the trailers with dinosaurs, and I drove commercial, part of our training was to keep the paperwork: Neat, complete and accurate. So mine for the tow and towed vehicles are in plastic bags in the glove box. The plastic prevents water and coffee damage. Keep them in the same place so you can find them. Police of all kinds like the paper work in order. If we are crossing the border, as others have said the passports, my yellow card and the dog's shot record is also in there. Now I will also add the covid records.